Background: The lung-brain-axis is an emerging area of study that got its basis from the gut-brain-axis biological pathway.

Objective: Using Respiratory Synctial Virus (RSV) as the model of respiratory viral pathogen, this study aims to establish some biological pathways.

Material and Methods: After establishing the mice model,the samples were sent to Wuhan GeneCreate Biological Engineering Co., Ltd for metabolomics analysis. In addition, Hematoxylin-eosin staining, indirect immunofluorescence (IFA) and RT-qPCR were also carried out to establish the pathological changes.

Results: RSV infection promoted epithelial shedding and infiltration of inflammatory cells. Also, RSV immunofluorescense and titres were significantly increased. Moreover, IL-1, IL-6 and TNF-αwere also significantly increased after RSV infection and the cell structure of hippocampal CA1 area was loose and disordered. Inflammatory cytokines IL-6 and IL-1βexpression in the brain also increased however, TNF-αexpression showed no differences among the control and RSV group.We observed an increased expression of IBA-1 and decreased NeuN neuronal. In addition, RSV mRNA expression levels were also increased and15 metabolites were found upregulated in the RSV group including nerve-injuring metabolite glutaric acid, hydroxyglutaric acid and Spermine.  Finally, ɑ-Estradiol increased significantly while normorphinedecreased significantly at day 7 of infection among the RSV group.

Conclusion: This study established a mouse model for the metabolomics model, and utilised hematoxylin-eosin staining, IFA and RT-qPCR to establish the pathological changes. It reported epithelial shedding and infiltration of inflammatory cells post RSV infection, along with RSV immunofluorescence and increased titres.

Keywords: Lung brain axis, Metagenomics, Metabolomics, Rsv infection, Neurons

Abbreviations: RSV: Respiratory Synctial Virus; IFA: Indirect Immuno Fluorescence